chainingactionfactoryproxy.java

webwork source

/*
 * WebWork, Web Application Framework
 *
 * Distributable under Apache license.
 * See terms of license at opensource.org
 */
package webwork.action.factory;

import webwork.action.*;
import webwork.config.Configuration;
import webwork.util.BeanUtil;

import java.util.Iterator;
import java.util.List;

import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.Log;


/**
 * Action Factory proxy to handle action chaining.
 * Adds actions performed to the action chain and copies properties
 * from each action to the next.
 *
 * @author Maurice C. Parker ([e-mail])
 * @version $Revision: 2 $
 */
public class ChainingActionFactoryProxy
   extends ActionFactoryProxy
{
   // Attributes ----------------------------------------------------
   protected static Log log = LogFactory.getLog(ChainingActionFactoryProxy.class);
   // Default max linked actions is 10
   protected int maxLinks = 10;

   // Constructors --------------------------------------------------
   public ChainingActionFactoryProxy(ActionFactory aFactory)
   {
      super(aFactory);
      try {
         maxLinks = Integer.parseInt(Configuration.getString("webwork.action.chain.maxlinks"));
      } catch(IllegalArgumentException e) {
         log.warn("Unable to retrieve maximum chain action property. Defaulting to 10.");
      }
   }

   // ActionFactory implementation -------------------------------
   public Action getActionImpl(String aName)
      throws Exception
   {
      // Get action from factory
      Action action = getNextFactory().getActionImpl(aName);
      ActionContext context = ActionContext.getContext();

      List actions = (List) context.get("action.chain");

      if (actions != null) {
	       if ((actions.size() + 1) > maxLinks) {
	         throw new IllegalStateException("Exceeded maximum number of chained actions = " + maxLinks);
	       }
           for (Iterator iter = actions.iterator(); iter.hasNext();) {
                BeanUtil.copy(iter.next(), action);
           }
	       actions.add(action);
       }

      // Return action
      return action;

   }
}